快速排序算法

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#include <iostream>       
using namespace std;   
int BinarySearch(int a[],int x,int n);  
int main()  
{  
    int x = 6;  
    int a[10];  
    for(int i=0; i<10; i++)  
    {  
        a[i] = i + 1;  
    }  
    cout<<BinarySearch(a,x,10)<<endl;  
    return 0;  
}  

int BinarySearch(int a[],int x,int n)  
{  
    int left = 0;  
    int right = n-1;  
    while(left<=right)  
    {  
        int mid = (left + right)/2;  
        if(x == a[mid])  
        {  
            return mid;  
        }  
        if(x>a[mid])  
        {  
            left = mid + 1;  
        }  
        else  
        {  
            right = mid - 1;  
        }  
    }  
	return -1; 
	}